In semiconductor device fabrication processes, a resist film is formed on a process target film formed on a substrate such as a semiconductor wafer (hereinafter referred to simply as “wafer”), and a process such as etching, ion implantation, etc. is performed to the process target film using the resist film as a mask. After the process, the resist film that is no longer necessary is removed from the wafer.
The removal of the photoresist film commonly uses an SPM (Sulfuric Acid Hydrogen Peroxide Mixture) process. The SPM process is performed by supplying to the photoresist film an SPM liquid which is a solution obtained by mixing sulfuric acid and a hydrogen peroxide solution.
In general, the SPM process is performed by supplying the SPM liquid from a chemical liquid supply nozzle to the spinning wafer retained in a horizontal position on a substrate retaining part. During the SPM process, since high-temperature SPM liquid is ejected toward the wafer, fumes comprising a vapor or a mist of reaction products of the SPM liquid and the resist are produced. Members surrounding the space near the wafer are provided to prevent the fumes from spreading and from contaminating the interior of a processing chamber. For example, in the apparatus described in Japanese Patent Application Publication No. JP2007-035866A, the edge of a wafer is surrounded by a splashguard (hereinafter, also referred to as “cup”) for receiving the process liquid, and a shielding plate (hereinafter, also referred to as “top plate”) is placed above the wafer upper surface (i.e., process target surface), whereby dispersing of the fumes is prevented.
However, a gap must be provided between an upper portion of the cup and the top plate to allow the passage of a nozzle support member for supporting the chemical liquid supply nozzle. Accordingly, fumes leak through this gap. A need may also arise for the SPM process to be followed by another chemical liquid cleaning process that uses the same apparatus. In this case, since the SPM liquid and fumes are highly contaminative, it is desirable to avoid cross contamination.